Pressure extractor



Dec. 19, 1933.

ASHER PRES SURE EXTRACTOR Filed Feb. 25. 1929 3 Sheets-Sheet l DEC. 19, 1933. w. J ASHER PRES SURE EXTRACTOR Filed Feb. 25, 1929 3 Sheets-Sheet 2 Patented Dec. 19, 1933 UNITED STATES PATENT orricE 1,939j15r PRESSURE ExrRAoroR William J. Asher, Colorado Springs, Colo. Application February 25, 1929. Serial No. 342,614`

`19 claims. (ci. 10o-So) l The present invention relates to pressure extractors for use in laundry work in removing the water from articles of apparel and the like after they have been washed, as a step preparatory to ironing, and particularly to appliances of this type in which the water is extracted from the various articles by positive pressure as compared with the centrifugal force of the common centrifugal extractor.

This application is a continuation in part of my copending application, Serial No. 187,668, filed April 29, 1927.

Several forms of extractors of the positive pressure type have heretofore been designedor suggested, but have not come into use, practically all power dryers now being used in laundry Work being of the centrifugal type. A carelessly assembled mass of wet clothing or textile fabrics has never the same resistance to compression between parallel surfaces throughout, and if subjected to pressure between such surfaces it always happens that some portions will have been subjected to the maximum pressure available or desirable before the water has been completely expressed from the remainder. Only a portion of the Watercontained in the mass can be removed by such a machine. p

The present invention contemplates the use, in a laundry extractor of the pressure type, of cooperating pressure elements of such character that the difficulty mentioned above, i. e. incomplete extraction, is overcome, the material being distributed laterally to a certain extent as the elements approach each other, as a result of their peculiar configuration, preferably dished or formed as concave surfaces, so that theV mass of goods therebetween is subjected to substantially the same pressure per unit area throughout each cross section therethrough, thus giving uniform extraction of the liquid.

It is therefore an important object of the present invention to provide an extractor of the positive pressure type in Which the material being compressed may laterally adjust itself during compression.

While it is desirable to use substantially hemispherical, relatively movable pressure surfaces when the chamber is relatively short, it is not so necessary to provide surfaces of this configuration when the chamber is relatively long as compared to its diameter. They may be fiattened somewhat when the chamber is long as Vcompared to its diameter.v Furthermore, cooperating pressure elements having stilldifferent surface configurations may be employed provided the necessary lateral adjustment of the mass of articles to be compressed is realized. Preferably the chamber is cylindrical in shape, although this is not essential.

In accordance with the present invention, a

locking mechanism is employed which provides a means for continuously attaching the cover to the extractor body throughout almost its entire perimeter and in such a manner that there is practically no chance of the cover becoming loose or distorted, even under the highest pressure to which the extractor may be subjected, as may occur where the cover is attached only at spaced points around its periphery.

It is therefore a further object of the invention to provide a locking device to interlock the cover and cylinder over substantially the entire periphery of the cover. Y

One of the novel features of the invention is the means for collecting the extracted liquid for delivery into a drain pipe and a further novel feature resides in a handle for the extractor cover, which constitutes a stop for preventing the cover from mashing the upper rim of the cylinder.

Finally, I provide a pressure extractor having means whereby the contained articles may be subjected to the action of a current of air while undergoing mechanical compression, the removal of the water being effected partially by the mechanical pressure applied and in part as a result of the action of such air current.

Other objects will be apparent from the following description and the accompanying drawings, in which one form of the invention is illustrated by way of example, but it will'be understood that the design and arrangement of the various vcomponent elements thereof mayV be altered to suit particular adaptations and that the invention is not limited to that particular embodiment which is illustrated and herein described in detail.

In these drawings:

Figure 1 is a vertical longitudinal section through the extractor, sections of the cylinder being broken out to shorten the gure;

Y Figure 2 is a vertical axial section through the extractor plunger, the plane of this section being at right angles to the plane of the section 105 of Fig. 1;

Figure 2a is a section through a plunger detail;

Figure 3 is a top plan View of the extractor Showing the locking mechanism for the cover; 119

Figure 4 is an enlarged vertical section taken along the line 4 4 of Figure 3;

Figure 5 is an enlarged cross section taken along the line 5-5 of Fig. 1;

Figure 6 is a vertical section along the line 6-6 of Fig. 5, showing the details of the operating mechanism for the locking ring;

Figure 7 is a detail Vvertical sectional vie somewhat enlarged, showing another portion of the cover; and

Figure 8 is a partial vertical section of a lower corner of the extractor cylinder showing the inlet connection.

Figure 9 is a somewhat diagrammatic view showing the installation of a battery of pressure extractors of various dimensions and capacities.

The pressure chamber of the positive pressure extractor comprises in general a wall, a head, and a plunger. It will be appreciated at the outset that these elements may be constructedy of various materials and may have various shapes. The embodiment ofv the invention which is illustrated in the drawings has been found to be entirely satisfactory in actual test, but without departure from the spirit of the invention, other shapes and material may be employed where desired. A

Making the wall 10 of the chamber cylindrical, however, promotes simplicity of construction, ease of assembly, reduces the cost oi fabrication and provides awall of maximum strength for a given weight of metal. The various parts of the apparatus are preferably formed of rust resisting materials, as they are subjected to the continual presence Yof moisture while in operation. Thus bronze is suitable, having the requisite strength to withstand the relative heavy pressures and the abilityv to resist corrosion. As a refinement, a stainless steel liner 11 is provided for the wall 10, and provides very accurate working surfaces for the movable plunger, a well as preventing corrosion. Y

The closure for'the bottom 12 vof the Wall 1'0 may be cast integral withthe wall as shown in Fig. k1. The bottom is essentially iiat, but bulges slightly upward as at 13, and provided with a central threaded aperture 14, in which is fitted a plug 15. An inlet into the bottom of the chamber is provided by a tapped opening 16 (Fig. 8), adapted to receive 'a supply pipe through which uid, either gas or liquid, is supplied under pressure from any available source.

Snugly tted within the liner 1l, or the wall of.

the cylinder 10 when no'liner kis provided, is a movable plunger 20. This plunger is also preerably of rust resistant metal andfabricated to have the necessary strength to resist the strains 'incident to high working pressuresV and-resistances; The plunger has an upper member 21 which makes Contact vwith the articles to be subjected tov pressure, and a transverse lower member 22 bolted to the horizontal lower annular surface thereof, an annular cup leather 23 being interposed between the upper and rlower members and securely clamped in position therebetween, for the purpose of eiiecting the snug fluid-tight t of the plunger with the walls oi the chamber. This lower member has transverse plate portion 24 which comprises the lower wall of an air space 25,"the upper wall of this air space being the upper member 21. A skirt 26 is formed integral with the plate 24, this skirt comprising a guide. Vertical grooves 26 `formed in the exterior'surface of the guide permit passage of fluid from the space below member 22 to the annular space 26" immediately below the packing leather 23. A removable plug in a vertically disposed portion of plate 24 is indicated at 27 and a conduit for conducting iiuid into chamber 25 is indicated at 28, the passage of uid through this conduit being controlled by a valve 29, the plug 27 and valve 29 being both accessible through an aperture 30 formed in the skirt. Pressure member 21 is likewise provided with a plurality of apertures 103. The functions of the various elements just described will hereinafter fully set forth.

"The upper surface er the plunge` is dished so as to centralise the material in the chamber and the pressure thereon, and obviously for an extractor in which the length is great in proportion to the diameter, the plunger will not be dished as much as it would in case the length is small in proportion to the diameter. In the form shown, the upper .s riace of the plunger is spherical at the central portion' 21a,"but -is conical at its outer edges 2lb, terminating in a sharp rim 21e. Both the upper surface and the vperiphery of the plunger are preferably tinned, as la positive guard against corrosion.V v

The head 35 is also preferably constructed of rust resisting material, and its lower surface is also spherical, the radius being such that its margin has a steep slope,as at 37, terminating in a rim 38, of slightly'greater diameter than the liner 11. r:this difference in diameter provides an annular orice to permit the escape of the extracted liquid, and aiso forms an overhang which prevents any articles from being cut when the cover is lowered, or caught or torn between the edges of the cover and'cylinder when pressure is applied. It is desirable to tin the lower surface of the cover including the rim 38.

An Vannular rim 43 is provided at the upper edge of the casing V10 and may be cast integral therewith. This rim forms a sump 44 which serves to collect the extracted liquid which overflows the upper edge of the 'linen As shown, the sump or channel 44 formed by the rim is deeper' yat the back of the machine, so that the liquid drains to the rear'and is conducted away by the drain pipe 45. Y

The vupper edge of the rim 43 is flat, and determines the working height of the extractor, inasmuch as the' operator must reach over this rim. Thelmost convenient height for this purpose has been determined, and for this reason the rim 43 is located at approximately thirtytwo inches from the floor of the laundry, irrespective of the length ofthe chamber 10. As the extractors will generally be of greater length, a lateral flange is secured to the wall 10, or may cast integral as shown. This flange is located at the specified distance below the rim 43 and is provided with a plurality oi bolt holes 51 by means of which it may be bolted to the supporting floonsuch as illustrated at 110 in Figure 9. Hence, as in the form shown, the extractor is' of greater length than thirty-two inches, and a suitable opening will be cut in the floor and the lov/'er end will be let down into the opening so that the flange 50 may rest on the supporting door.

Thus, shown in Figure 9, the manufacturer may produce a series of extractors otvarious capacities which may vary in diameter as well length, and still provide each of the series with the same feature of mest convenient working height, by locating the flange 50 at the same about the pintle 53.

distance, indicated at A, below the rim 43, irrespective of thev size of the particular unit. Y

With this arrangement convenience in charging and discharging of the chamber isY provided. When the extraction is completed and the cover is opened, the plunger will lift the extracted goodsA out of the chamber, in the` form of a column resting on the upper surface thereof, and at a convenient height so that they are entirely accessible to the operator who may readily take the goods therefrom all at once, or in successive portions as desired.

rIhe cover 35 is supported byV a rearward extension 52, which has xed therein a horizontal pintle 53, journaled in gudgeons 54 formed in bosses at the edges of a cutaway portion 55 of the rim 43. A counter-weight 56 extends rearwardly from the cover and serves to balance it The cover is provided with an abutment 57 and thel counterweight arm 58 is secured to the top thereof by means of machine screws 59. The central portion of the arm 58 rests on the flattened upper edge of the cover hinge member 52, and is drilled to receive securing means 92 threaded in the member 52. The counter-weight 56 is cut away at its lower side, to provide a concave surface 93 of they same curvature as the wall 10, and rubber plugs 94 are mounted therein to project above the surface, so that when the cover is opened to its fullest extent, the plugs 94 abut against the side of the wall` l0 and prevent marring of its surface by impact ofthe counter-weight.

As shown in Fig. 1, the cover is provided with a heavy annular flange 60 andan operating handle 61 is secured to the upper side of the flange by machine screws 62 andprojects out over the rim 43 at 63 and then extends downwardly to receive an operating knob 64. The portion 63 projecting over the rim 43 forms a stop which prevents the cover rim 38 from mashing the upper edge of the cylinder, as well as preserving thespaced relation of the parts constituting the annular orice forl extraction of the liquid.

For securing the cover in place very strongly so as to withstand the heavy pressures contemplated, means are provided for a continuous grip between the cover and wall. As best shown in Fig. '7, the inner edge of the rim 43 is provided with an annular shoulder 65 and the flange 60 is provided with an annular groove 66 which receives a ring 67, shown as rectangular in cross section and adapted to be expanded outwardly to engage under the shoulder 65, 'thus providing a continuous locking for the cover.

The means for expanding and contracting the ring is best shown in Figs. 4, 5 and 6. A short vertical shaft 70 is journaled in the counter- Weight arm 58, and is provided with oil holes' 71 for lubrication. The upper end of the shaft is of reduced diameter to receive a crank 72, secured thereon by a set screw 73. and provided vwith an operating knob r74. Lugs upstanding from the arm 58 limit the throw of the crank.

The lower end of the shaft 70 projects below the arm 58 and terminates in a reduced pivot 77 which is journaled in a socket 78 formed in the hinge member 52. Shorter pivot pins 79 are eccentrically and oppositelyv mounted in the shoulder 80 on each side of the pivot 77. The pins 79 respectively engage holes in the ends of substantially semicircular links 82 and 83, which are in turn pivoted respectively to the ends 67a and 6.71) of. the locking ring 67.

The link 82 slides laterally along a widened portion 84`of the bottom of the groove 66, and other means are provided for slidably supporting the `link 83. For this purpose, a support member.` 85 is provided, having a boreY 86 rotatably receiving the pivot '77v and a fiat vertical edge 87 engaging a rectangular recess 88 in the member 52, so as to prevent its rotation. The member 85 has also a shelf portion 90 extending outwardly to form a seat for the link 83.

The operation of the locking devise is best shown in Fig. 3, in which turning the knob to the position shown in full lines-will bring the links 82 and 83 to the position shown in Fig,.r5. This contracts the ring, drawing it back into the groove 66 so as to clear theannular shoulder 65, and permits the cover 35 to be raised by the operator grasping the knob 64 and moving it upward. VM

When the cover is closed and knob 74 is turned to the position shown in dotted lines in Fig. 3, the link 83 slides along the ilange' 90 and the link 82 slides along the surface 84, forcing the ends 67a and 67h apart, expanding the ring 67 so that it extends outwardly under the annular shoulder 65 substantially around its entire periphery, thus providing a uniform locking for the entire periphery of the cylinder.`

In the operation of the extractor, and assuming the plunger 20 to be in its lowermost position and the hinge cover tilted so that the interior of the cylinder is accessible, the` operator will deposit as many wet or damp articles of clothing or textile fabric within the cylinder as he mayrplace therein, that is, the cylinder is i'llled to its capacity with laundry articles. The cover is then rotated to closed position and locked in this position in the manner hereinbefore described.

As soon as the cover is closed, air under pres sure from any suitable source may be admitted to the bottom of the cylinder beneath the plungerand as soon as the pressure in the space beneath the plunger has built up suiflciently, the

plunger begins its upward movement, compressing the articles above it between its upper surface and the lower surface of the cover. This action is continued until the plunger has reached the upper limit of its travel, that is, when the pressure uponthe upper surface of the plunger, due to the articles under compression and the pressure` below the plunger due to the compressed air, have become equal. Next the air pressure below the plunger is slightly reduced by manipulating a release valve so that the pres` sure of the garments against the cover is relieved. Following this, the cover is moved to open position and thereafter additional air may be admitted to the cylinder beneath the plunger to bring the plunger to the upper limit of its travel, projecting the clothing or other articles being extracted above the top of the'cylinder and into such 'position that they are entirely visible to the operator and may be either lifted or pushed fromthe extractor onto atable or L).

into a basket.

It will be understood from an inspection of Fig.V 1, that no air will escape from beneath the plunger until the packingrings 23 have been raised slightly above the upper chamiered edge thereby providing an annular Vorifice through which air may freely escape from the annular space26" which is in communication with the pressure chamber by means of the grooves 26', and so reducing the pressure upon the bottom of the plunger that its further movement iS halted. As a safeguard, however, against ejection of theA plunger from the mouth of the Cylinder, it is kpositively secured to the bottom by means of chains, indicated at 100, the upper ends of these chains being secured to member 24 by means of screw bolts 101 and the lower ends of these chains being secured by means oi a bolt 102 to the axial plug l5 in the bottom of Y very considerable portion of the plunger may be raised to a position above the upper end of the cylinder so that no diiicultyv/ill be met with in having the plunger again passed to the bottom of the cylinder.

Of course, the slots 26 alone or in conjunction with the annular space 26 would be effective in relieving the pressure beneath the piston in order to halt its'upward movement without the provision of the chamfered edge on the liner 11. While it is true that the liner, in cooperating with the grooves, might eiect a more gradual relief of pressure, the device would be completely operative if the chamfering of the edge were omitted and the grooved skirt 26 were to pass upwardly beyond a straight cylindrical inner surface at the upper margin oi the chamber. Another possible function of the chamfering of the liner is to aid in guiding and centering the packing material 23 upon the return movement of the piston.

The method of operation just described may be carried out either with air or water as .the motive fluid, the valve 29'having been closed during such operation. I preferto operate the plunger, however, with air as the motive fluid and to utilize a portion of the air introduced into the cylinder to create a current of air which flows continually during the extracting operation upwardly through the cylinder from the plunger, through the column of articles superimposed upon the same, and out ofthe discharge orifice through which the extracted water ilows. I have found that such a vertically rising column of air assists in the extraction of liquid from the garments to a considerable degree, thereby rendering it unnecessary to employ such higlr pressures as are requisite when mechanical pressure alone is relied upon.` Thus, in'performing the operation of extraction in accordance with this last suggested method, the valve 29 is wholly or partially opened, thus allowing a portion of the compressed air entering the base oi the cylinder to pass upwardly into the space 25. From this space it passes into the cylinder above the plunger 20 through a plurality of relatively restricted oriiices 103. The air passage from the orifices 103 intothe chamber above the plunger is at a considerably reduced pressure, that is, at a pressure which is considerably lower than the pressure of the air below the plunger and which is serving to propel the same upwardly inasmuch as its volume greatly restricted by means of the control. 'valve 29. Sufficient air is admitted, however, throug the oriiices 103 to create a considerable dra-ft up through the garments or other textile articles under treatment and this column of air carries The skirt 26 of the plunger mainofi with it a considerable quantity of the contained moisture. As a result, the extraction is performed in part by mechanical pressure and in part by the drying effect of an air column.

For the purpose of holding the plunger in its elevated position while the articles from which the water has been extracted are being removed, and without necessitating the maintenance of air pressure below the plunger, a mechanical latch is provided. This latch, which is indicated at 105, is pivotally mounted at 106 within a recess formed in the side of the upper member of the plunger. The center of gravity of the latch lies to the right of its pivotal axis (Fig. 1) and its lower end normally rests against a portion of the plunger, whichconstitutes a stop.

When the plunger has been raised to such height that the latch is uncovered, pressure of the fingers upon its upper end will cause its lower end to swing outwardly to overlie the upper edge of the cylinder, so that when the plunger is slightly lowered, the latch engages the cylinder and the plunger retained in this position. To unlatch the plunger it must be raised slightly, whereupon the latch will automatically fall back to the position in which it is shown in Fig. 1. As it may sometimes be necessary to opcrate the extractor when only partially lled with garments or the like, there is some chance that, upon the applicationof heavy pressure, the charge will be so compressed that the edge of the plunger will strike the curved surface of the cover. To prevent injury to the plunger edge, in the event that this occurs, the under surface o the coverl is grooved as indicated at 107, to

provide a striking surface for the plunger edge which is transverse to the direction of plunger movement. Contact with this striking surface does not tend to inturn the plunger edge as does contact with the normally inclined lower surface A ofthe cover.

Having thus described the invention, what is claimedas new and desired to be secured by Letters Patent is:

1. An extractor for removing water from cloth '5 goods and the like by subjecting a mass of such goods to a substantially uniform pressure per unit of area throughout, comprising two pressure applying and goods distributing members, said Y members being relatively movable to apply pressure to goods positioned therebetween and having their mutually facing surfaces concave so as to distribute the goods laterally as the members approach each other, and means associated with said members for laterally confining the goods for all working positions of said members.

v2. A pressure extractor for laundry use, comprising a pair of vpressure surfaces concaved and relatively movable toward each other along a common axis to express liquid from materialtherebetween, the radial slopes of said surfaces at their extremities making acute angles with the common axis.

3. In a pressure extractor comprising a cham- Der hWHg a plunger movable therein, a cover se having a smoothly curved concave surface terminating in a rim, the slope of said surface at said 'rim making an angley greater than 45 degrees with the plane of said rim.

4. In a pressure extractor for laundry purposes, comprising a chamber having a cylindrical wall, a cover, and a plunger movable toward the cover to express liquid from material contained therein, said cover being dished providing a marginal rim of greater diameter than the u'p'pc'r rim of said cylinder, and said cylinder being iprovldedwith an annular flange of greater diameter than the cover rim and extending beyond the rim of the cylinder, the 'combination of a radially projecting handle f or said cover,

a portion of said handle extending oversaidV annular flange and constituting a stop adapted to rest upon said annular flange to prevent said cover from contacting with the rim of said cylinder.

5. In a pressure extractor for laundry pur-1 poses, comprising a chamber havinga' head constituting a cover and a liquid tight plunger movable upwardly therein to express liquid from material contained therein over the upper rim of the chamber wall, means for introducing a pressure medium below said plunger to force it upwardly, and means for relieving the pressure beneath the plunger at a point on its upward travel prior to the time when the pressure would cause ejection of the plunger from the chamber, said means including a beveled portion of the upper rim of the chamber wall.

6. In a pressure extractor for laundry purposes comprising a chamber having a head constituting a cover and a liquid tight plunger movable upwardly therein to express liquid from material contained therein over the upper riml of the chamber wall, means for introducing a pressure medium below said plunger to force it upwardly, means on said chamber wall for relieving the pressure beneath the plunger at a point on its upward travel4 prior to the time when the pressure would cause ejection of the plunger from the chamber. the total height ofl the outer edge of. said plunger being greater than the distance of said relieving means from the upper rim of the chamber whereby the plunger may lift the extracted goods above the chamber rim, and means for guiding and centering said plunger with respect to said chamber during said lifting movement.

7. In combination with a series of pressure extractors for laundry purposes, each comprising a vertical chamber having a removable upper head constituting a cover yand a plunger movable upwardly therein, to express liquid from material contained therein said chambers being of varying lengths, of supporting means Vcommon to the series for supporting said chambers vertically with the upper ends at a uniform convenient height from the supporting floor.

8. In combination with a series of pressure extractors for laundry purposes each comprising a vertical chamber having a removable upper head constituting a cover and a plunger movable upwardly therein to express liquid from material contained therein, said chambers being of varying lengths, of supporting means common to the series for supporting said chambers vertically with their upper ends at approximately thirty-two inches from the supporting floor, said means including supporting ilanges surrounding said chambers spaced this distance from the upper ends, and each adapted to engage the margin of a hole in the supporting floor receiving the lower portion of the chamber.

9. In a pressure extractor the combination of means to facilitate discharge of the extracted material, comprising a chamber, a head constituting a cover therefor and a plunger movable in said chamber, a cut away portion at the upper end of said chamber' for relieving the pressure under said plunger, the height ci said plunger exceeding the vertical extent of said cut away portion, 'whereby the plunger may lift the extracted goods above the chamber rim,V

and means for guiding and centering said plunger during said'lifting movement.

l0. An extractor for removing water from cloth goeds or the like by subjecting a 'mass of such goods to a substantially uniform pressure perunit of area throughout, comprising a cylinder, a cylinder head, and 'a plunger working in said cylinder, the plunger making fluidtight contact with the cylinder walls, said head and plunger having mutually facing concave pressure applying surfaces adapted to Vproperly distribute the goods laterally as pressure is applied thereto, the cylinder head being spaced slightly from the end of the cylinder to provide an orifice for the escape of water, which orifice lies in advance of the plunger for all working positions thereof.

11. In a pressure extractor for laundry purposes, comprising a chamber, a plunger movable therein and having a huid tight nt with the wall thereof, means for introducinga pressure medium into said chamber on one side of said plunger to force it toward one end of said chamber, and means for relieving the pressure on said plunger at a point in its travel toward said end of the chamber prior to the time when the pressure would cause ejection of the plunger from the chamber, said means including a skirt on said plunger provided with a series of grooves upon its chamber Wall contacting surface.

l2. The combination set forth in claim l1 in which there is provided additional means for preventing ejection of the plunger comprising an elongated exible connecting member one end of which is secured to said plunger and the other end to the opposite end of said chamber.

13. The combination set forth in claim 1l ir which each of the grooves extends throughout the length of said skirt and communicates at j one of its'ends with the interior of said chamber -pressure is applied.

14. An extractor for removing liquid from cloth goods or similar material, comprising in combination, a chamber, a fluid `pressure actuatedplunger movable in said chamber to compress said material therein to extract the liquid therefrom, and means for subjecting said material to the action of a portionV of the pressure fluid within said chamber.

l5. An extractor for removing liquid from cloth goods or similar' material, comprising in combination, a chamber, a plunger movable in said chamber to compress said material therein, means for introducing a pressure uid at one end of said chamber for actuating said plunger, means for subjecting said material to the action of said pressure fluid within said chamber to aid in drying said material and means for withdrawing said liquid and said pressure fluid at the other -end of said chamber.

15. An extractor for removing liquid from cloth goods or similar material, comprising in combination, a chamber, a head at one end of said chamber, a plunger movable in said chamber, having a iiuid tight nt with the wall thereof, and adapted to compress said material between one of its surfaces and said chamber head, means for introducing air under pressure at the opposite end of said chamber for actuating said plunger, said plunger being perforated whereby a portion ofy said air may pass to the opposite side thereof and asisst in drying said material,

and an outlet for said liquid and said drying air at the head end of the chamber.

17. The combination set forth in claim 16 in which said plunger is provided with an adjustable valve for regulating the amount of drying air permitted to pass through the perforations in said plunger.

18. The combination as set forth in claim 16 in which said plunger is double walled, the Wall at the material compressing side being provided with a. series of small perfor-ations, and the other Wall being provided with a valve opening, whereby the amount of drying air permitted to pass through the material may be regulated.

. material contained therein, a projecting stop member on said cover adapted to abut another of said portions, said member and the hinge constituting the only means for preventing the cover from contacting With. said upper rim of said cylindrical wall.

WILLIAM J. ASHER. 

